2ob7
Structure of tmRNA-(SmpB)2 complex as inferred from cryo-EM
Structural highlights
FunctionSSRP_AQUAE Binds specifically to the SsrA RNA (tmRNA) and is required for stable association of SsrA with ribosomes. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA eubacterial ribosome stalled on a defective mRNA can be released through a quality control mechanism referred to as trans-translation, which depends on the coordinating binding actions of transfer-messenger RNA, small protein B, and ribosome protein S1. By means of cryo-electron microscopy, we obtained a map of the complex composed of a stalled ribosome and small protein B, which appears near the decoding center. This result suggests that, when lacking a codon, the A-site on the small subunit is a target for small protein B. To investigate the role of S1 played in trans-translation, we obtained a cryo-electron microscopic map, including a stalled ribosome, transfer-messenger RNA, and small protein Bs but in the absence of S1. In this complex, several connections between the 30 S subunit and transfer-messenger RNA that appear in the +S1 complex are no longer found. We propose the unifying concept of scaffolding for the roles of small protein B and S1 in binding of transfer-messenger RNA to the ribosome during trans-translation, and we infer a pathway of sequential binding events in the initial phase of trans-translation. Scaffolding as an organizing principle in trans-translation. The roles of small protein B and ribosomal protein S1.,Gillet R, Kaur S, Li W, Hallier M, Felden B, Frank J J Biol Chem. 2007 Mar 2;282(9):6356-63. Epub 2006 Dec 19. PMID:17179154[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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